Die rolling and article produced thereby



Sept 20, 1932. v w p QW 1,878,054

DIE ROLLING AND ARTICLE PRODUCED THEREBY Original Filed Feb; 7, 1925 2 Sheets-Sheet l INVENTOR p 1932- w. P. WITHEROW DIE ROLLING AND ARTICLE PRODUCED THEREBY 2 Sheets-Sheet 2 Original Filed Feb. '7, 1925 f 12. A C

T W i FFJ4 Patented Sept. 20, 1932 UNITED STATES PATENT OFFICE WILLIAM WITHEROW, OFI'ITTSBURGH, PENNSYLVANIA, ASSIGNOB, BY MESNE -AS- SIGNMENTS, TO REPUBLIC STEEL CORPORATION, OF JERSEY CITY, NEW JERSEY, A

CORPORATION OF NEW JERSEY DIE ROLLING AND ARTICLE PRODUCED THEREBY Application filed Februaryv 7, 1925, Serial No. 7,470. 'Benewed May 25, 1932.

The present invention relates broadly to netal working, and more particularly die roll closedand claimed a method of die rolling comprising utilizing a leader having ama or- I blank produced.

- Heretofore in narily been considered ofimportance only to' provide a leader having a sufiicient cross section to properly form the desired blanks. In my co-pending application. Serial No. 530,640, filed Januarv 20, 1922, i have (11sand a minor axis. v I have found that-a leader having a major and a minor axis is of decided advantage in that it facilitates the die rolling operation and improves the character of the Heretofore, for the successful die rolling of articles, arrangement has been made for the production of a substantial amount of flash, such .flash facilitating the reduction to be effected on the leader and assisting in the rolling of blanks to accurate dimensions within the close tolerances permitted I't'will be apparent, however, that this flash niust neces- 'sarily be trimmed before the blanks can be used, and that the amount of waste metal is.

-' directly proportional to the amount of flash.

The present invention has for one of its objects the provision of a leader by means of which the amount of flash may be materially reduced and the production of blanks facili- Ordinarily, such matrix portions have been of a character to produce uniform reduction circumferentially of an article in the event of circular shapes, and usually to produce reduction both vertically and transversely relative of the shapes being rolled. lVhile this operation is perfectly feasible and practicable for certain shapes, I have found that for other shapes such an operation is exceedingly hard on the rolls, the reduction not being equal throughout the entire length of the blanks andimposing unequal wear on the matrix portions of thegrooves at different points. Furthermore, the formation of the rolls is expensive due to the fact that the grooves must necessarily be formed throughout, due to their varying dimensions, on a die sinking or other similar machine.

The present invention has for further of its objects a method of die rolling-by means ofwhich the length of life of the rolls is increased and the cost of the rolls is materially decreased and in'which substantiallyall of the reduction is effected in a plane substantiafilSy-normal to-the axis of rotation of the r0 In the accompanying drawings I have tain preferred embodiments of the present invention, it being understood that the drawings do not define the limits of my invention and that changes in the construction and operation disclosed therein may be made without departing either from the spirit of the invention or the scope of my broader claims.

In the drawings: I

Figure 1 is an outline illustrating the configuration of a leader adaptedfor the formatloclil ef a blank such as shown in Figures 2 Figure 2 is a side elevation of a. cam shaft blank produced in accordance with the present invention;

Figure 3 is a top plan view of the blank shown in Figure 2;

Figure 4: is a transverse sectional view on any of the lines IV IV of Figures 2 and 3;

Figure 5. is a -transverse sectional view on any of the lines VV of Figures2 and 3;

Figure 6 is an end elevation of a portion of a pair of rolls adapted for the production of a horse shoe blank;

Figure 7 is a side elevation illustrating a connected series of blanks produced by the rolls shown in Figure 6; v

shown for purposes of illustration only cer- Y orlO;

Figure 8 is an end elevation of the blank F ig'ure 10 is a top plan view of the blank.

shown in Figure 9;

Figure 11 is a transverse sectional view- XI=XI of Figures 9' along" any of the lines Figure 12 is a transverse sectional view along any of the lines XII-. XII of Figures 9 or 10;

Figure .13 is a'transverse sectional View along any of the lines XIII-XIII of Fi ures 9 or 10; and

.igure 14 is an outline similar to Figure 1 illustratin a form of leaderadapted, for example, for the production of a steering knuckle in accordance with the present invention. r

The present invention is distinguished from the prior art among other things by reason of the fact that substantiallyan'y section taken through a blank produced by die rolling in accordance herewith is substantially rectangular. irrespective of the shape of the transverse section of the finished article to be produced therefrom as contrasted fromthe generally circular shape heretofore frequently imparted to blanks by the d1e rolls. k It has been found that in thls manner the percentage of flash produced can be materially reduced while simplifying the d1e rolling operation. The present invention is further characterized by the production of a blank of substantially constant width, the var ations be ng only in a vertical directlon, or direction lying in aplane normal to the axis of rotatlon of the rolls. The leader utilized will also aproximate arectangle as a limit, the leader having a major and a minor axis.

The ma] or axis representing the height of the blank is preferably slightly in excess of the height of the rolled blank to provide the necessary draft and the width of the leader is preferably substantially equal to but slightly less than the width of the rolled blank.

The percentage of reduction effected by the die, rolls, hereafter designated as R, is determined by the formula:

LA-SA I in which LA is equal to the large'area or normal area of the leader and SA is equal to the smaller area at the point at which the In practicing the present invention the following relations preferably exist:

the foregoing, w represents the average width of the die rolled blank and k the maxlmum height of the die rolled blank at any point.

Referring specifically to Figure -l of the drawings there is disclosed the transverse outline of a leader which has been found to' be highly successful for use in the die rolling of cam shafts and particularly cam shafts of the character suitable for the production of finished cam shafts for a standard automobile. Such a leader has a width slightly less than 1 inches and a height slightly less than 3 inches, it having been found that very desirable results are produced where IV equals 1 inches and H'equals 37% inches.

lVith such a leader the blank,shown in F igures 2 and 3 and in cross section in Figures 4 and 5 can be effectively produced. In actual practice, it has been found that with a finished trimmed weight for the blank of 15.6 pounds the total weight of the flash will not exceed 1' pound or slightly more than 6 per cent of the weight of a complete blank, this being materially less than it has heretofore been possible to produce in the ordinary practice of die rolling.

Referring to Figure 5 in which the maximum height of the die rolled blankis shown, It preferably equals 2 inches, this being slightly smaller than H, and 10, represent ing the average width of the die rolled blank, is 1% inches, this being slightly greater than W. This blank satisfies the following formulae:

I W or 'w H W H h It will be noted that the configuration of the leader shown in Figure l approaches a A rectangle as a limit, the leader, however, having slightly rounded ends 2 and fiat sides 3. i

I believe that in using a leader of this character one reason for the small amount of flash is directly attributable to the substan- .By keeping these portions slightly curved,

the use of sharp corners is entirely obviated and the matrix portions of the die rollsare more completely filled. In the blank, the enlarged portions 4 provide sufficient stock tially straight sides, in which the metal is not initially so disposed asto facilitate latfor the subsequent finishing by forging or otherwise of the cams while the smaller portions 5 are adapted to form the bearing portions of the cam shaft. From an inspection of Figure 3 as compared to Figure 2 it will be seen that the die rolled blank is of sub-Y stantially constant width but of varying height at different portions. In this partic tially 69 per cent. the value of It being subular example, the percentage reductionon opposite sides of 'amedian plane passing transversely through the blank from side to side is uniform, the work, being distributed equally between the rolls.

/ I have also found that in carrymg out the present invention very desirable results are obtained where the side walls 6 of the (he ,rolled blank converge upwardly and downwardly from an intermediate plane, this plane in the form of the invention shown in Figures 2 to 5- being a median plane through the blank. n -Figure 4 the angle of convergence is designated AC, this angle being approximately 7. In igure 5 the corresponding angle is "designated ac,'th1s angle 1n this instance being approximately 4. It will be noted that the angle of convergence decreases as the value of h increases, it-having been found from actual practice that with such a construction it is possible to obtain a better filled blank and at the same time provide a blank which frees itself more readily from the die rolls. a

In Figures 6, 7 and 8 there are shown different features of the invention'applicable to the production of a'horsesh'oe blank. In

this embodiment of the invention the lower roll 8 has a matrix groove 9 herein shown as being of constant depth and preferably of constant width throughout the entire periphery of the roll. The upper roll 10, how ever. has a matrix groove 11 of varying dimensions as to depth throughout the periphery ofthe roll but preferably of substantially constant width, the direction of rotation of the rolls being indicated by tl1e.ar-

row A. These rolls are adapted for the pro duction' of the blank shown in Figures 7' and 8, in which the blank is of substantially constant width, the base 12 being formed in the matrix groove 9 of the bottom roll and lying in a common plane while the upper portion is formed by the matrix groove 11 in the upper roll. The flash formed during the rolling operation is designated F,-' this flash being most pronounced adjacent the portions of smaller cross sectional area where the value of R increases. By reference to Figure 8 of' the die rolled blank l ksu ch as adapted for the production of an automobile front axle, has a substantially constant width. but varies symmetrically as to' height on opposite sides of a median plane. In Figure 12 there is illustrated the minimum cross-sectional area of the die rolled blank, this area representing a reduction in actual practoice of substanstantially 7 inch in this section as compared to 2 inches in Figure 13 which represents the maximum section in which, however, theremostcases this angle should not be materially less than 4 and need not be materially greater than 7 although this latter figure may be 7 increased materially if desired.-

In Figure ll there is illustrated the configuration of another 'leader in which H may equal, for example, 4 inches and W 2 4 inches, it being desired to produce from this leader a blank in which 11; shall be equal to substantially 2 73 inches and in which-the maximum value of'h is 4 inches. This condition also fulfills the following formulae:

W or =40 H h H W It is not essential in the carrying out of the present invention that the sides of the blank shall lie in parallel planes,hitbeing possible to slightly curve the same whileretaming certain of the advantages of theinvention. In all, cases. however, the radius of curvature of the sides should be greater than the radius of curvature of the ends or'the top and. bottom of the. leaderandthe percentage of flash is materially reduced and the shaping of the-articlefacilitated.

By practicing an invention'in which sub-' stantially all of the reduction is accom- 4 plished in a plane normal to the axis of rotation of the rolls, itwill be apparent that it is possible to utilize matrix grooves, in the rolls having a substantially constant width. This permitsthe rolls to be initially placed in an ordinary lathe bymeans of which a groove is turned therein having a width substantially equal to the desired width of the finished matrix portion and having a minimum depth substantally equal tothe minimum depth of such matrix portion. Thereafter the sides of the groove may be maof the major portion of the groove in the lathe or similar machine, as contrasted to my hand.

the usual process of forming the same in a die sinking machine or die routing indicator represents a material saving not only in time but also'in investment. I. have also found that by filleting all of the corners, and curving the bottoms of the grooves in both rolls, when combined with the diverging Wall relationship to give the desired angle of convergence in the vfinished blank, crushing down. of the rolls is prevented and the length of life materially increased.

7 The advantages of the present invention arise from a method of die rolling resulting in decreased cost, increased length of "life of the die rolls and a decrease inthe per;

centage of flash.

I claim: l

1. A die rolled blank having a substantially constant width and having at least a portion of the side walls converging upwardly the. blank being of varying height at different portions and having an angle of in height.

2. A die rolled blank having a substantial- 1y constant width and having at least a porconvergence decreasing as the blank increases tion of its side walls conver ing downwardly, the blank being of different height in different portions thereof and having an angle of convergencedecreasing as the blank increases in height, substantially as described. 3. The method of die rolling,- comprising utilizing a uniform leader of quadrangular section having curved topand bottom walls tion alon scribed,

and producing therefrom a blank having a substantially rectangular cross section at any point, said blank being of varying cross secits. length, substantially as dew liereby the production of flash and the wear on the rolls is reduced.

4. The method of die rolling, comprising utilizing a uniform leader having curved side Walls of a greater radius than the top and bottom Walls and producing therefrom a blank of substantially rectangular cross section at any point, the blank being of varyving cross section along 1ts length, substantially as described, whereby the greatest reduction occurs in a plane perpendicular to the roll axis.

5. The method of die rolling, comprising supplying'a leader of quadrangular section and having curved top and bottom faces, to a die rolling pass, geducing the leader in all parts in the pass so as to form a blank having a substantially rectangular cross section at any point, the cross sectional area of the blank differing at different parts thereof, there being flash along the sides of the blank chined or otherwise finished and the bottom tially as described, whereby the maximum of the groove further machined to impart reduction is effected in a the desired depth thereto. This formation lar to the roll axis.

WILLIAM r. wrrHERoW.

in at least certain portions thereof,'substan- I 

